Nir-Ii Emissive Superoxide Radical Photogenerator for Photothermal/photodynamic Therapy Against Hypoxic Tumor.

Due to the "Achilles' heels" of hypoxia, complicated location in solid tumor, small molecular photosensitizers with NIR-II fluorescence, type-I PDT, and PTT have attracted great attention. However, these photosensitizers are still few but yet challenging. Herein, we present an "all in one" NIR-II A-D-A fused-ring photosensitizer, Y6-Th, for the in-depth diagnosis and efficient treatment of cancer. Benefiting from the strong intramolecular charge transfer, promoted highly efficient intersystem crossing, largely π-conjugated fused-ring structure, and reduced planarity, the fabricated nanoparticles (Y6-Th NPs) could emit NIR-II fluorescence with the peak located at 1020 nm, exclusively generate O 2 • - for type-I PDT and display excellent PTT performance under an 808 nm laser stimulation. These characteristics make Y6-Th a distinguished NIR-wavelength-triggered phototheranostic agent, which could effectively therapy the hypoxic tumor using NIR-II fluorescence-guided type-I PDT/PTT. This work provides a valuable guideline for fabricating high-performing NIR-II emissive superoxide radical photogenerators. This article is protected by copyright. All rights reserved.